Composite article



W. H. KEMPTON.

COMPOSITE ARTICLE.

APPLICATION FILED AUG. I0. 1918.

1 09,758, Patented Jul 15, 1919.

2 SHEETS-SHEET l- WITNESSES: Pg 6 INVENTOR w. H. KEMPTON COMPOSITE ARTICLE.

APPLICATION FILED AUG-10' I918. 1 ,309,75& Patented July 15, 1919.

2 SHEETS-SHEET 2.

WILLARD H. KEIVIIIEWION, 0F

INGHOUSE ELECTRIC 8: PENNSYLVANIA.

1,309,758. Original application filed June WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WEST- MANUFACTURING COMPANY, A CORPORATION OF COMPOSITE ARTICLE.

1918. Serial No. 249,349.

To all whom it may concern: 1

Be it known that I, WILLARD H. KEMP- TON, a citizen of the United States,and a resident of \Vilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Composite Articles, of which the following is a specification, this being a division of application Serial No. 242,499, filed June 28, 19 8.

My invention relates to composite articles and it has for its primary object to provide an article composed of two or more different molding compositions and which may be molded at a single operation.

Oftentimes, it is very desirable that various parts of an article shall possess diiferent qualities and, in many instances, such articles are of a character which will permit of being formed by molding Heretofore, it has been the practice, under such circumstances, to mold the several parts as separate elements and to then assemble the parts by an adhesive or other suitable means to form the complete article.

An example showing the desirability of forming articles having certain portions of one maternl and other portions of another will readily occur to anyone skilled in the molding art. For-instance, in some articles it is necessary that a certain portion or portions have unusually high dielectric properties while th remaining portions need not have such properties or may require ability to withstand the heat of flash-overs and arcs. Again, with some articles, the main body of the article need not possess as great strength as that required in certain portlons of the article and, under such circumstances,foftentimes, the main body may be formed of'a more economical composition thanthe portions requiring strength. .Furthermore, insome instances certain portions of an article must possess extremely high wearing properties while the remaining portions. are in no Way subject to wear.

To insure a clear understanding of my invention, I have disclosed a method by which articles having difi'erent portions of their bodies formed of different molding compositionsmay be quickly, economically and efliciently formed and molded, as a unit,

in a single operation.

Obviously, although manykinds of moldprinciples should be adhered to.

ring; Fig. 4

view of a bushing 'has been found that tions of-the ring ties to as great an extent but must be capeployed and wide changes in the comb1na-- tions thereof, in a single article, may be made to obtain the best results, certain broad For exthe various molding compositions or materials employed should all be susceptible of being cured under the same treatment or, at least, the treatment required for one of ample,

the materials should be such as to insure the curing of all the other materials employed.

Furthermore, the materials employed should be of such nature that the coeflicients of expansion of the materials, when they are cured, will be substantially the same in order that there shallbe no tendency toward distortion of the article, either during its curing or while it is in use, In addition to these features, in most instances it is desirable that the various materials employed be of such relative natures that-they will unite with each other to form strong joints between the several portions of the article.

In the drawings, in which corresponding reference numerals indicate like parts throughout the several ,yiews, I have illustrated two quite different examples of articles which may be constructed by practising my invention, the first of these belng a barrier ring for alternating-current motors an the second, a bushing for electrical insulating purposes.

In the drawings, Figure 1 is a plan view of a barrier ring constructed in accordance with my invention ;,Fig. 2 is a sectional view taken on the line II-IIof Fig. 1; Fig. 3 is a'plan viewof one form of mold which may be employed in making the barrier is a central vertical sectional view, taken on the line IV.IV of Fig. 3, showing a barrier ring within the mold and Fig. 5 is a central longitudinal sectional constructed in accordance with my invention.

In constructing alternating current motors, barrier rings are sometimes interposed between the contact rings and must possess certain insulative' and .flash-over or arc-resisting properties. With, large motors, it

these barrier rings must possess extremely high dielectric qualities while the outer porneed not possess such qualithe inner portions of to mold the material 3.

'ble of withstanding flash-overs and arcs.

Difliculty has been met with in obtaining a desirable material possessing both of these properties and it, therefore, seems advisable to construct the barrier rings of difl erent materials.

In Figs. land 2, I have illustrated a barrier ring comprising an annular body 1 made up of superimposed layers of fibrous material impregnated with a binder. The fibrous material which may preferably be employed s sheet asbestos, andthe binder may be a phenolic condensation product, such as bakelite,'which will harden under the action of heat and pressure. Secured against the opposite sides of'the annular body 1 are rings 2 and 3 of a different material, these rings being of the'same internal diameter as the body l'butof less external diameter so that the periphery of'the body 1 projects considerably beyond them. These rings may be formed of any suitable molding material having high dielectric properties, such as wood flour impregnated with a suitable binder as, for instance, a'phenolic condensation product. I

In practising my invention, the body'is formed and positioned without being cured in a suitable mold with a sufficient-amount of the other molding material to form the rings after which the body thus assembled is cured in any suitable manner, as by sub j ecting it to the action'of heat and pressure, if the binder be a'phenolic condensation product.

By this means, a unitary article is'provided, the several portions of which possess difi'erent qualities. The body portion, being of sheet asbestos and a hardened phenolic condensation product, is capable of resist ing flash-overs and arcs while the remaining portions of the barrier ring, being of wood flour and a phenolic condensation product, possess unusually high dielectric properties.

In Figs. 3 and 4, I ha've illustrated'a form of mold which maybe em 'loyed in'practising my invention. As t ere shown, the mold comprises inner and 'outer-body-f'orming rings 4 and 5 which are concentrically disposed with respect 'to' each other and 'be tween which is disposed at bottom-forming be wall or ring 6 upon which 'may 'be placed the sheet material 1 of the barrier rln -The upper surface'of this 'bottom'ring'fi'i formed with an annular recess 7 corresponding to the portion'2 of the barrier rin and-adapted to receive the material of whic said portion is made. Cooperating with these mold sections are the outer and inner pressure rings 8 and 9, the former of which "is adapted to engage the marginal portion of the sheet material 1 and the latter of which is adapted The manner of molding the barrier ring will be readily appreciated by reference to phenolic condensation and heat-withstanding capacity. further illustrated tary'bodies may 'bemolded at a single opera Fig. 4 of the drawings. The inner and outer wall-forming rings 4 and 5 and the bottom-forming ring 6 are disposed in operative relation, suiiiclent material for the 1 ormation of the portion 2 of the 'barrler ring is then placed upon the recessed portion, of the ring 6, the desired quantity of stacked sheet material is placed in the mold,

the'pres surering sisapplied, sufiicient adin theinold and bring them toproper shape.

Heat is applied to the mold simultaneously withthe pressure and-is continued for such length of time as to insure that the assembled barrier-ring structure within the mold shall be fully compacted and hardened to form a strong unitary body.

"In Fig. 51 have illustrated a simple, type of bushing Which'may be constructed in accor-dance with my invention and which comprises a'tubular body lO-provided, at one end, with an external annular collar 11. 'Ihe body 10 may be formed of any suitable fibrous "Sheet material, such as paper or fabric'impregnated with a suitable binder, as, for instance, a phenolic condensation product, the sheet material being wound about a'proper mandrel or core to form a tube having a wall *of desired thickness.

en this'has been done, the tube is placed in a properly shaped mold, together with suflicient molding material of a different character toform the collar 11, and is there subjected'to' heat'and pressure to shape and solidify both the tube and collar to form a "unitary article. Any suitable molding material may be used for the formation of the collar 11 which will be cured by the same treatment as that required to cure the tubular body portion 10. For instance, a

"shredded material, such 'asasbestos, may be employed or =a finely divided comminuted matemaL-such as wood flow, may be used, together "with a suitable binder, such as a product.

From'the, foregoing description, it will apparent that I have provided a system of multiplex molding which permits of the employment of two-or more molding compositi ons in "the formation of a single unitary article. it "will further be apparent that this permits-the employment of molding compositions having difi'erentcharacteristics of mechanical strength, dielectric strength I "have a method by which unition in which portions 'of the body are formed-of laminated fibrous or fabricated sheet material impregnated with a binder while other portions may be formed of a finely divided, comminuted, agglomerated or shredded filler impregnated with a suitable binder. Shellac, copal, casein and other binders may be employed instead of a phenolic condensation product if desired.

A hard, rigid non-yielding article is formed by reason of the character of the binder employed and the process of curing utilized although, as will be noted, the binder employed is initially inactive and is rendered active only by the curing of the assembled article.

Although I have illustrated but two examples of articles, constructed in accordance with my inventive process, and although I have set forth the employment of a phenolic condensation product, such as bakelite, for a binder and utilization of paper and asbestos and wood flour as fillers, it will be appreciated that numerous other binders and fillers may be empolyed to form various articles. For this reason, no limitations are to be imposed upon my invention other than those set forth in the claims.

I claim as my invention:

1. A hard and rigid composite molded article comprising agglomerated material,

a non-metallic laminated material of relatively great tensile strength and a heathardehed binder intimately associated with and uniting said materials.

2. A hard and non-yielding composite molded article comprising an agglomerated,

comminuted material, a non-metallic material of relatively great tensile strength and a hardened binder intimately associated with and hardening and uniting saidmaterials,

3. A hard and rigid composite molded article comprising an agglomerated, comminuted material, a fabricated material, and a common binder intimately associated with and hardening and uniting the said materials.

4. A hard and rigid composite molded article comprising an agglomerated, comminuted material, a sheet fibrous material and a common binder intimately associated with and hardening and uniting the said materials:

5. A hard and non-yielding composite molded article comprising an agglomerated material, a plurality of layers of fibrous material and a common heat-hardened binder intimately associated with and uniting the said materials.

6. A hard and non-yielding composite molded article comprising localized portions &

of a shredded or comminuted material and a fabricated material and a common hardened binder intimately associated With and hardening and uniting the said materials.

In testimony whereof, I have hereunto subscribed. my name this 7th day of August,

' WILLARD KEMPTON. 

